What is stomach cancer?

Cancer is made of changed cells that grow out of control. The changed (abnormal) cells often grow to form a lump or mass called a tumor. Cancer cells can also grow into (invade) nearby areas. And they can then spread to other parts of the body. This is called metastasis.

The stomach is made of different layers. The mucosa is the deepest layer. It makes stomach acid and the enzymes that digest food. Most stomach cancers start in the mucosa. There’s also a thick muscle layer that helps mix up food.

There are different types of stomach cancer. They each grow in different parts of the stomach.

Who is at risk for stomach cancer?

A risk factor is anything that may increase your chance of having a disease. The exact cause of someone’s cancer may not be known. But risk factors can make it more likely for a person to have cancer. Some risk factors may not be in your control. But others may be things you can change.

The risk factors for stomach cancer include:

• Being in your 60s or older

• Being a man

• Being Hispanic, African American, Asian, or a Pacific Islander

• Eating a lot of smoked, salted, pickled, and cured foods, and a diet low in fruits and vegetables

• Smoking

• Drinking lots of alcohol

• Being overweight or obese, especially men

• Working in the coal, metal, and rubber industries

You also have a higher risk if you have:

• Blood type A

• Infection with a germ or bacteria called Helicobacter pylori (H. pylori). H. pylori can cause stomach inflammation and ulcers.

• Had stomach surgery in the past for noncancer diseases, such as ulcers

• Low red blood cell levels because you can’t absorb vitamin B12 (called pernicious anemia)

• Stomach growths (polyps called adenomas)

• Long-term inflammation of the stomach lining (also called gastritis)

• A disorder called common variable immune deficiency (CVID). This hurts the immune system so that it doesn’t fight germs well.

• Family members with certain conditions, such as:

  • Stomach cancer (a parent, brother, or sister)

  • Hereditary diffuse gastric cancer

  • Hereditary nonpolyposis colorectal cancer or Lynch syndrome

  • Familial adenomatous polyposis

  • Li-Fraunmeni syndrome

  • Leutz-Jeghers syndrome

  • Breast cancer gene mutations BRCA1 and BRCA2 

Talk with your healthcare provider about your risk factors for stomach cancer and what you can do about them.

Can stomach cancer be prevented?

You may be able to lower your risk for stomach cancer by making some lifestyle changes. These include:

• Not eating much smoked, salted, pickled, and cured foods, and increasing fruits and vegetables in your diet

• Staying at a healthy weight

• Not smoking

• Not drinking alcohol or drinking only a little

What are the symptoms of stomach cancer?

The symptoms of stomach cancer vary from person to person. In early stages, you may have mild or no symptoms. The most common symptoms include:

• Stomach pain or discomfort above the navel level

• Feeling full or bloated after eating even small amounts of food

• Nausea and vomiting soon after eating

• Vomiting blood

• Diarrhea or constipation

• Blood in your bowel movements (stool)

• You don’t feel like eating

• Losing weight without trying

• Feeling weak and tired

Stomach cancer that’s more advanced can block your stomach or intestines. This can cause vomiting that doesn’t go away. Stomach cancer can also spread to your liver. If this happens, it can cause yellowing of your skin and the white part of your eyes (jaundice) or fluid buildup in your belly (abdomen) called ascites.

Many of these may be caused by other health problems. So it's important to see a healthcare provider if you have these symptoms. Only a healthcare provider can tell if you have cancer.

How is stomach cancer diagnosed?

Your healthcare provider will ask you about your health history, your symptoms, risk factors, and family history of disease. They will also give you a physical exam. You may have a fecal occult blood test to check for blood in your stool, blood tests, an upper endoscopy to look at your stomach inner lining and biopsy abnormal areas, or an upper GI series (also called a barium swallow).

A biopsy is the only way to confirm cancer. Small pieces of tissue are taken usually during the endoscopy procedure and checked in a lab by a pathologist for cancer cells. Often, the biopsy is done during an endoscopic procedure while sedated so you won't feel pain. Your healthcare provider will use a tool or small knife to remove tissue from the abnormal area that may be stomach cancer. The samples are sent to a lab. Special tests on the tissue will be done to check for gene or protein changes that may help with treatment decisions (such as MSI, PD-L1). Your pathology results will come back in about 1 week, but the other test results may take longer.

After a diagnosis of stomach cancer, you may have other tests, such as CT scans. These help your healthcare providers learn more about the cancer. They can help figure out the stage of the cancer. The stage is how much and how far the cancer has spread (metastasized) in your body. It is one of the most important things to know when deciding how to treat the cancer.

Once your cancer is staged, your healthcare provider will talk with you about what the stage means for your treatment. Ask your provider to explain the stage of your cancer to you in a way you can understand.

How is stomach cancer treated?

Your treatment choices depend on the type of stomach cancer you have, test results, and the stage of the cancer. Other things to think about are if the cancer can be removed with surgery and your overall health. The goal of treatment may be to cure you, control the cancer, or help ease problems caused by cancer. Talk with your healthcare team about your treatment choices, the goals of treatment, and what the risks and side effects may be.

Types of treatment for cancer are either local or systemic. Local treatments remove, destroy, or control cancer cells in one area. Surgery and radiation therapy are local treatments. Systemic treatment is used to destroy or control cancer cells that may have traveled around your body. When taken by pill or injection, chemotherapy, targeted therapy, and immunotherapy are systemic treatments. 

Stomach cancer is treated with surgery, radiation therapy, chemotherapy, immunotherapy, or targeted therapy. You may have just one type of treatment or a combination of treatments. 

Talk with your healthcare providers about your treatment choices. Make a list of questions. Think about the benefits and possible side effects of each choice. Talk about your concerns with your healthcare provider before making a decision.

What are treatment side effects? 

Cancer treatment, such as chemotherapy and radiation, can damage normal cells. This causes side effects, such as hair loss, mouth sores, and vomiting. Talk with your healthcare provider about side effects you might have with all types of treatment and ways to manage them. There may be things you can do and medicines you can take to help prevent or control side effects.

Coping with stomach cancer 

Many people feel worried, depressed, and stressed when dealing with cancer. Getting treatment for cancer can be hard on your mind and body. Keep talking with your healthcare team about any problems or concerns you have. Work together to ease the effect of cancer and its symptoms on your daily life.

Here are some tips:

• Talk with your family or friends.

• Ask your healthcare team or social worker for help.

• Speak with a counselor.

• Talk with a spiritual advisor, such as a minister or rabbi.

• Ask your healthcare team about medicines for depression or anxiety.

• Keep socially active.

• Join a cancer support group in person or online.

Cancer treatment is also hard on the body. To help yourself stay healthier, try to:

• Eat a healthy diet, with a focus on high-protein foods.

• Drink plenty of water, fruit juices, and other liquids.

• Keep physically active.

• Rest as much as needed.

• Talk with your healthcare team about ways to manage treatment side effects.

• Take your medicines as directed by your team.

When should I call my healthcare provider?

Your healthcare provider will talk with you about when to call with any concerns. You may be told to call if you have any of the following:

• New symptoms or symptoms that get worse

• Signs of an infection, such as a fever

• Side effects of treatment that affect your daily function or don’t get better with treatment

Ask your healthcare provider what signs to watch for, and when to call. Know how to get help after office hours and on weekends and holidays.

Key points about stomach cancer

• There are different types of stomach cancer. Most types start in the innermost layer of the stomach, called the mucosa. It makes stomach acid and the enzymes that digest food.

• Risk factors include being a man, in your 60s or older, and being Hispanic, African American, or a Pacific Islander.

• Lifestyle changes may help to reduce risk of stomach cancer. These include not eating smoked, salted, pickled, and cured foods. They also include staying at a healthy weight, not smoking, and not drinking.

• In early stages, there may be mild or no symptoms. The most common symptoms include stomach pain, diarrhea or constipation, vomiting blood, and feeling full or bloated after eating even small amounts of food.

• Stomach cancer is treated with surgery, radiation therapy, chemotherapy, immunotherapy, or targeted therapy. One or more types of treatment may be used.

Next steps 

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions, especially after office hours or on weekends.